A Competitive Strategic Position Analysis of Major Container Ports in Southeast Asia

Viet Linh DANG,여기태 한국해운물류학회 2017 The Asian journal of shipping and Logistics Vol.33 No.1

The importance of planning strategies to achieve higher competitiveness has become more apparent in the context of seaports since seaports have been encountering quickly changing and highly competitive business environments. Therefore, the strategic competitive position of seaports needs to be investigated using strategic positioning methods. The purpose of this study was to analyze the competitive positions of the top 20 container ports of five countries in the Association of Southeast Asian Nations (ASEAN-5) in six years from 2009 to 2014 using dynamic portfolio analysis. This study aims to fill the gap in research on the competitive strategic position and analysis of Southeast Asian container ports in order to allow seaport operators to visualize the position and progress of selected ports as well as to predict the future development possibilities of seaports. The findings revealed effective operations at the following ports that retained their dominant positions during the duration of the study: Port Klang, Tanjung Pelepas (Malaysia), Manila (the Philippines), Laem Chabang (Thailand), and Tan Cang Sai Gon (Vietnam). However, findings revealed a common deterioration at other ports studied.

Weighing the Key Factors to Improve Vietnam’s Logistics System

Viet Linh DANG,Gi-tae YEO 한국해운물류학회 2018 The Asian journal of shipping and Logistics Vol.34 No.4

Over the past 20 years, Vietnam has signed more free trade agreements than any other country in the region, becoming one of the world's largest integrated economies. Nonetheless, Vietnam's logistics costs are still higher than the association of southeast Asian nations (ASEAN) average, which has reduced its ability to participate in the global value chain. These higher costs are also reflective of the country’s inefficient logistics system, which can be confirmed by the fact that Vietnam's Logistics Index (LPI) fell from 48 in 2014 to 64 in 2016. Therefore, Vietnam is in urgent need of improving its national logistics in system. By applying the consistent fuzzy preference relations (CFPR) method for weighing main factors influencing the improvement of Vietnam’s logistics system, this study indicates a direction for the Vietnam government to follow in implementing the ideal investment prioritization and the appropriate regulations for the improvement of its logistics system. The results reveal that the optimal order for the improvement of Vietnam’s logistics system are logistics costs, logistics services, logistics infrastructures, connections between logistics components, institutional frameworks, and technology. The study also provides logistics stakeholders with increased insight into the status of Vietnam’s logistics system and the appropriate strategies for achieving the goals of its government.

A concentration pattern analysis of port systems in South East Asia

Viet Linh Dang,여기태 한국해양수산개발원 2016 해양정책연구 Vol.31 No.2

During the past few decades, Southeast Asia has experienced rapid growth in the number of containerized cargo transported through the port systems, particularly in the ASEAN-5 group, which includes Indonesia, Malaysia, the Philippines, Thailand, and Vietnam. As a result, container ports in the ASEAN-5 nations have experienced intensive development. This paper aims to clarify the spatial evolution process of these container ports through estimating degrees as well as the trends concentration by applying the Hirshmann-Herfindahl Index (HHI), a concentration ratio (CR3), and shift-share analysis (SSA). The results of this analysis reveal that a tendency toward deconcentration has been occurring in the container ports of Vietnam and Indonesia, a trend that is in contrast to the systems of other ASEAN-5 nations, all of which have experienced a concentration trend. The numbers of containers have also beed shifted significantly within intra-port systems. Moreover, the differences of concentration patterns are clarified through port governance’s development policies.

Influence of Crystallite Size on Magnetocaloric Effect and Critical Behavior La_0.7Sr_0.3Mn_0.92Co_0.08O₃ Nanoparticles

Tran Dang Thanh,Dinh Chi Linh,Le Viet Bau,Thi Anh Ho,Tien Van Manh,The-Long Phan,Seong-Cho Yu IEEE 2015 IEEE transactions on magnetics Vol.51 No.1

<P>Four samples of La<SUB>0.7</SUB>Sr<SUB>0.3</SUB>Mn<SUB>0.92</SUB>Co<SUB>0.08</SUB>O<SUB>3</SUB> (LSMCO) with different crystallite sizes were prepared by the combination of solid-state reaction and mechanical milling methods. Based on isothermal magnetization data, M(H), temperature dependences of magnetic entropy change, ΔS<SUB>m</SUB>T, of the samples under a magnetic field change of 10 kOe were calculated. The maximum values of magnetic entropy change (|ΔS<SUB>max</SUB>|) at room temperature are in the range of 0.9-1.4 J · kg<SUP>-1</SUP> · K<SUP>-1</SUP>, corresponding to ferromagnetic (FM)-paramagnetic phase transition. In addition, M<SUP>2</SUP> versus H/M curves at temperatures around TC prove the samples exhibiting a second-order magnetic phase transition. The critical exponents β, γ, and δ were determined using the modified Arrott plot method and critical isotherm analysis. Here, these exponent values are located in between those expected for the mean-field theory and 3-D Heisenberg model. It means the coexistence of short-range and long-range FM interactions in LSMCO nanoparticles.</P>

Na-doped La_0.7Ca_0.3MnO₃ compounds exhibiting a large magnetocaloric effect near room temperature

Chi Linh, Dinh,Thi Ha, Nguyen,Huu Duc, Nguyen,Giang Nam, Le Huu,Bau, Le Viet,Manh An, Nguyen,Yu, Seong-Cho,Dang Thanh, Tran Elsevier 2018 PHYSICA B-CONDENSED MATTER - Vol.532 No.-

<P><B>Abstract</B></P> <P>In this work, we have investigated the magnetic properties and the magnetocaloric effect of La<SUB>0.7−x</SUB>Na<SUB>x</SUB>Ca<SUB>0.3</SUB>MnO<SUB>3</SUB> compounds, which were prepared by a conventional solid-state reaction technique. The Rietveld refinement results suggested that the samples are single phase belonging to an orthorhombic structure (space group <I>Pnma</I>). Analyzing temperature dependence of magnetization <I>M</I>(<I>T</I>) revealed that the Curie temperature (<I>T</I> <SUB>C</SUB>) increases with increasing Na content (<I>x</I>). Their <I>T</I> <SUB>C</SUB> value is found to be 260–298K for <I>x</I>=0.0–0.1, respectively. Base on <I>M</I>(<I>T</I>) data measured at different applied magnetic fields (<I>H</I>), temperature dependence of magnetic entropy change Δ<I>S</I> <SUB>m</SUB>(<I>T</I>) data for all the samples was calculated by using a phenomenological model. In the vicinity of <I>T</I> <SUB>C,</SUB> -Δ<I>S</I> <SUB>m</SUB>(<I>T</I>) curve reaches a maximum value (denoted as |Δ<I>S</I> <SUB>max</SUB>|), which gradually increases with increasing <I>H</I>. Under 12kOe, the value of |Δ<I>S</I> <SUB>max</SUB>| is in a range of 1.47–5.19J/kgK corresponding to the relative cooling power RCP=57.12–75.88J/kg. Applied the universal master curve method for the magnetic entropy change, we concluded that Na-doped in La<SUB>0.7−x</SUB>Na<SUB>x</SUB>Ca<SUB>0.3</SUB>MnO<SUB>3</SUB> compounds leads to modification the nature of the magnetic phase transition from the first- to the second-order.</P>

Understanding the COVID-19 Infodemic: Analyzing User-Generated Online Information During a COVID-19 Outbreak in Vietnam

Ha-Linh Quach,Thai Quang Pham,Ngoc-Anh Hoang,Dinh Cong Phung,Viet-Cuong Nguyen,Son Hong Le,Thanh Cong Le,Dang Hai Le,Anh Duc Dang,Duong Nhu Tran,Nghia Duy Ngu,Florian Vogt,Cong-Khanh Nguyen 대한의료정보학회 2022 Healthcare Informatics Research Vol.28 No.4

Objectives: Online misinformation has reached unprecedented levels during the coronavirus disease 2019 (COVID-19) pandemic. This study analyzed the magnitude and sentiment dynamics of misinformation and unverified information about public health interventions during a COVID-19 outbreak in Da Nang, Vietnam, between July and September 2020. Methods: We analyzed user-generated online information about five public health interventions during the Da Nang outbreak. We compared the volume, source, sentiment polarity, and engagements of online posts before, during, and after the outbreak using negative binomial and logistic regression, and assessed the content validity of the 500 most influential posts. Results: Most of the 54,528 online posts included were generated during the outbreak (n = 46,035; 84.42%) and by online newspapers (n = 32,034; 58.75%). Among the 500 most influential posts, 316 (63.20%) contained genuine information, 10 (2.00%) contained misinformation, 152 (30.40%) were non-factual opinions, and 22 (4.40%) contained unverifiable information. All misinformation posts were made during the outbreak, mostly on social media, and were predominantly negative. Higher levels of engagement were observed for information that was unverifiable (incidence relative risk [IRR] = 2.83; 95% confidence interval [CI], 1.33–0.62), posted during the outbreak (before: IRR = 0.15; 95% CI, 0.07–0.35; after: IRR = 0.46; 95% CI, 0.34-0.63), and with negative sentiment (IRR = 1.84; 95% CI, 1.23–2.75). Negatively toned posts were more likely to be misinformation (odds ratio [OR] = 9.59; 95% CI, 1.20–76.70) or unverified (OR = 5.03; 95% CI, 1.66–15.24). Conclusions: Misinformation and unverified information during the outbreak showed clustering, with social media being particularly affected. This indepth assessment demonstrates the value of analyzing online “infodemics” to inform public health responses.

Magnetic and magnetocaloric properties in second-order phase transition La_1−xK_xMnO₃ and their composites

Thanh, Tran Dang,Linh, Dinh Chi,Yen, Pham Duc Huyen,Bau, Le Viet,Ky, Vu Hong,Wang, Zhihao,Piao, Hong-Guang,An, Nguyen Manh,Yu, Seong-Cho Elsevier 2018 PHYSICA B-CONDENSED MATTER - Vol.532 No.-

<P><B>Abstract</B></P> <P>In this work, we present a detailed study on the magnetic properties and the magnetocaloric effect (MCE) of La<SUB>1−x</SUB>K<SUB>x</SUB>MnO<SUB>3</SUB> compounds with <I>x</I>=0.05–0.2. Our results pointed out that the Curie temperature (<I>T</I> <SUB>C</SUB>) could be controlled easily from 213 to 306K by increasing K-doping concentration (<I>x</I>) from 0.05 to 0.2. In the paramagnetic region, the inverse of the susceptibility can be analyzed by using the Curie-Weiss law, <I>χ</I>(<I>T</I>)=<I>C</I>/(<I>T</I>−<I>θ</I>). The results have proved an existence of ferromagnetic clusters at temperatures above <I>T</I> <SUB>C</SUB>. Based on Banerjee's criteria, we also pointed out that the samples are the second-order phase transition materials. Their magnetic entropy change was calculated by using the Maxwell relation and a phenomenological model. Interestingly, the samples with <I>x</I>=0.1–0.2 exhibit a large MCE in a range of 282–306K, which are suitable for room-temperature magnetic refrigeration applications. The composites obtained from single phase samples (<I>x</I>=0.1–0.2) exhibit the high relative cooling power values in a wide temperature range. From the viewpoint of the refrigerant capacity, the composites formed out of La<SUB>1−x</SUB>K<SUB>x</SUB>MnO<SUB>3</SUB> will become more useful for magnetic refrigeration applications around room-temperature.</P>

Magnetocaloric Effect in La_0.7Ca_0.25Ba_0.05MnO₃ Nanocrystals Exhibiting the Crossover of First- and Second-Order Magnetic Phase Transformation

Thanh, Tran Dang,Linh, Dinh Chi,Van, Hoang Thanh,Ho, Thi Anh,Van Manh, Tien,Bau, Le Viet,Phan, The-Long,Yu, Seng-Cho The Japan Institute of Metals 2015 MATERIALS TRANSACTIONS Vol.56 No.9

Some Results of Recent Investigation and Application of Rubber Blends in Vietnam

Bui Chuong,Nguyen Thanh Liem,Dang Viet Hung,Nguyen Huy Tung,Nguyen Pham Duy Linh,Nguyen Thanh Nhan,Pham Ngoc Linh,Le Anh Kien,Chu Chien Huu 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1

We have investigated the change of tensile strength (TS) of Natural rubber/chloroprene rubber (NR/CR) blends during combination ageing, including heating and dynamic mechanical loading. Using model of statistical experiment, we built the equation describing the dependence of TS on four factors: temperature T, number of cyclic loadings N, contents of NR (C_NR) and chloroprene (CCR). This equation allows predict the TS change of NR/CR blends after combination ageing with accepted inaccuracy – less than 10%. We also investigated the effect of nanofillers, such as nanoclay, SiO2, Fe₃O4, on adhesion of some rubber blends to polyester and steel cords. It was found, in the case of EPDM/CIIR rubber blends, both nanoclay and SiO2 have no effect on adhesion to steel cords, while nano SiO2 may enhance adhesion to polyester cords. On other side, Fe₃O4 may remarkably enhance adhesion of NR/CR blends to steel. Mentioned results are successfully applied in some practical rubber products working under fatigue conditions, such as rubber/steel antivibration pad for locomotive, heat resistant conveyor, water dam, underwater lift bag.

A Longitudinal Analysis of Concentration Developments for Container Terminals in Northern Vietnam

Thi Yen PHAM,여기태,Jun Woo JEON,Viet Linh DANG,Young Doo CHA 한국해운물류학회 2016 The Asian journal of shipping and Logistics Vol.32 No.3

Vietnam has been one of Asia’s fastest growing economies since 1990, with a steady growth of 6-8 percent. Vietnam’s container port throughput volume also increases impressively year by year, at around 6-8 percent since 2002. To cope with increasing cargo volume, the development of modernized container terminals in Northern Vietnam has intensified. This longitudinal study aims to identify the development of the system and, in particular, the concentration or deconcentration tendencies, as well as the geographical patterns from 2005 to 2014. In order to achieve the study’s objectives, the Herfindahl–Hirschman Index (HHI), concentration ratios (CR1, CR3), the Gini coefficient, the Lorenz curve, and shift-share analysis (SSA) were applied based on container throughput volume data from 2005 to 2014. The results demonstrate that the development of container terminals in Northern Vietnam has experienced a deconcentration trend and considerable shifting among its terminals during the period of observation. The proposed and validated research is original as it is the first study of concentration, deconcentration, and geographical patterns for container terminals in Northern Vietnam. The findings will enable port authorities, policy makers, and port operators to understand the development and changes of container terminal systems in Northern Vietnam more clearly.